feat: add createNamespace and deleteGeneratedNamespaces operations (#23)

Add namespace generation, tracking, and cleanup operations to support
dynamic namespace names in eval tasks. createNamespace generates a
namespace with a random hex suffix (e.g. vm-test-a1b2c3) and tracks it
internally. deleteGeneratedNamespaces cleans up all tracked namespaces,
silently ignoring already-deleted ones.

Ref: mcpchecker/mcpchecker#213

Signed-off-by: Matthias Wessendorf <mwessend@redhat.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: matzew

pkg/extension/extension.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 
 	"github.com/mcpchecker/mcpchecker/pkg/extension/sdk"
 	"k8s.io/client-go/dynamic"
@@ -17,6 +18,9 @@ import (
 type Extension struct {
 	*sdk.Extension
 	client ResourceClient
+
+	mu                   sync.Mutex
+	generatedNamespaces []string
 }
 
 // New creates a new Kubernetes extension

pkg/extension/namespace.go

@@ -0,0 +1,142 @@
+package extension
+
+import (
+	"context"
+	"crypto/rand"
+	"fmt"
+	"strings"
+
+	"github.com/mcpchecker/mcpchecker/pkg/extension/sdk"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+var namespaceGVR = schema.GroupVersionResource{Group: "", Version: "v1", Resource: "namespaces"}
+
+const alphanumeric = "abcdefghijklmnopqrstuvwxyz0123456789"
+
+// generateID returns a random lowercase alphanumeric string of the given length.
+// This matches the {random.id} spec from mcpchecker/mcpchecker#102.
+func generateID(length int) (string, error) {
+	b := make([]byte, length)
+	if _, err := rand.Read(b); err != nil {
+		return "", fmt.Errorf("failed to generate random id: %w", err)
+	}
+	for i := range b {
+		b[i] = alphanumeric[int(b[i])%len(alphanumeric)]
+	}
+	return string(b), nil
+}
+
+func (e *Extension) handleCreateNamespace(ctx context.Context, req *sdk.OperationRequest) (*sdk.OperationResult, error) {
+	if e.client == nil {
+		return sdk.Failure(fmt.Errorf("kubernetes client not initialized")), nil
+	}
+
+	args, ok := req.Args.(map[string]any)
+	if !ok {
+		return sdk.Failure(fmt.Errorf("args must be an object")), nil
+	}
+
+	prefix, _ := args["prefix"].(string)
+	if prefix == "" {
+		return sdk.Failure(fmt.Errorf("prefix is required")), nil
+	}
+
+	id, err := generateID(8)
+	if err != nil {
+		return sdk.Failure(err), nil
+	}
+
+	name := fmt.Sprintf("%s-%s", prefix, id)
+
+	obj := &unstructured.Unstructured{
+		Object: map[string]any{
+			"apiVersion": "v1",
+			"kind":       "Namespace",
+			"metadata": map[string]any{
+				"name": name,
+			},
+		},
+	}
+
+	e.LogInfo(ctx, "Creating namespace", map[string]any{
+		"name": name,
+	})
+
+	result, err := e.client.Create(ctx, namespaceGVR, obj, "")
+	if err != nil {
+		e.LogError(ctx, "Failed to create namespace", map[string]any{
+			"name":  name,
+			"error": err.Error(),
+		})
+		return sdk.Failure(fmt.Errorf("failed to create namespace: %w", err)), nil
+	}
+
+	e.mu.Lock()
+	e.generatedNamespaces = append(e.generatedNamespaces, result.GetName())
+	e.mu.Unlock()
+
+	e.LogInfo(ctx, "Namespace created successfully", map[string]any{
+		"name": result.GetName(),
+	})
+
+	return sdk.SuccessWithOutputs(
+		fmt.Sprintf("Created namespace %s", result.GetName()),
+		map[string]string{
+			"namespace": result.GetName(),
+		},
+	), nil
+}
+
+func (e *Extension) handleDeleteGeneratedNamespaces(ctx context.Context, req *sdk.OperationRequest) (*sdk.OperationResult, error) {
+	if e.client == nil {
+		return sdk.Failure(fmt.Errorf("kubernetes client not initialized")), nil
+	}
+
+	e.mu.Lock()
+	namespaces := make([]string, len(e.generatedNamespaces))
+	copy(namespaces, e.generatedNamespaces)
+	e.generatedNamespaces = nil
+	e.mu.Unlock()
+
+	if len(namespaces) == 0 {
+		return sdk.Success("No generated namespaces to delete"), nil
+	}
+
+	e.LogInfo(ctx, "Deleting generated namespaces", map[string]any{
+		"count":      len(namespaces),
+		"namespaces": namespaces,
+	})
+
+	propagation := metav1.DeletePropagationForeground
+	deleteOpts := metav1.DeleteOptions{
+		PropagationPolicy: &propagation,
+	}
+
+	var errs []string
+	for _, ns := range namespaces {
+		err := e.client.Delete(ctx, namespaceGVR, ns, "", deleteOpts)
+		if err != nil {
+			if apierrors.IsNotFound(err) {
+				e.LogInfo(ctx, "Namespace already deleted (ignored)", map[string]any{
+					"name": ns,
+				})
+				continue
+			}
+			e.LogError(ctx, "Failed to delete namespace", map[string]any{
+				"name":  ns,
+				"error": err.Error(),
+			})
+			errs = append(errs, fmt.Sprintf("%s: %s", ns, err.Error()))
+		}
+	}
+
+	if len(errs) > 0 {
+		return sdk.Failure(fmt.Errorf("failed to delete namespaces: %s", strings.Join(errs, "; "))), nil
+	}
+
+	return sdk.Success(fmt.Sprintf("Deleted %d generated namespace(s)", len(namespaces))), nil
+}

pkg/extension/namespace_test.go

@@ -0,0 +1,219 @@
+package extension
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/mcpchecker/mcpchecker/pkg/extension/sdk"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+func TestHandleCreateNamespace(t *testing.T) {
+	tests := []struct {
+		name        string
+		args        any
+		client      *mockClient
+		wantSuccess bool
+		checkOutputs func(t *testing.T, result *sdk.OperationResult, ext *Extension)
+	}{
+		{
+			name: "successful create",
+			args: map[string]any{
+				"prefix": "vm-test",
+			},
+			client: &mockClient{
+				createFn: func(ctx context.Context, gvr schema.GroupVersionResource, obj *unstructured.Unstructured, namespace string) (*unstructured.Unstructured, error) {
+					return obj.DeepCopy(), nil
+				},
+			},
+			wantSuccess: true,
+			checkOutputs: func(t *testing.T, result *sdk.OperationResult, ext *Extension) {
+				t.Helper()
+				ns, ok := result.Outputs["namespace"]
+				if !ok {
+					t.Fatal("expected namespace output key")
+				}
+				if !strings.HasPrefix(ns, "vm-test-") {
+					t.Errorf("namespace %q does not have prefix vm-test-", ns)
+				}
+				// ID should be 8 lowercase alphanumeric chars per mcpchecker#102
+				id := strings.TrimPrefix(ns, "vm-test-")
+				if len(id) != 8 {
+					t.Errorf("expected 8-char id, got %q (len=%d)", id, len(id))
+				}
+
+				ext.mu.Lock()
+				defer ext.mu.Unlock()
+				if len(ext.generatedNamespaces) != 1 {
+					t.Fatalf("expected 1 tracked namespace, got %d", len(ext.generatedNamespaces))
+				}
+				if ext.generatedNamespaces[0] != ns {
+					t.Errorf("tracked namespace %q != output namespace %q", ext.generatedNamespaces[0], ns)
+				}
+			},
+		},
+		{
+			name:        "invalid args type",
+			args:        "not a map",
+			client:      &mockClient{},
+			wantSuccess: false,
+		},
+		{
+			name: "missing prefix",
+			args: map[string]any{
+				"other": "value",
+			},
+			client:      &mockClient{},
+			wantSuccess: false,
+		},
+		{
+			name: "client error",
+			args: map[string]any{
+				"prefix": "vm-test",
+			},
+			client: &mockClient{
+				createFn: func(ctx context.Context, gvr schema.GroupVersionResource, obj *unstructured.Unstructured, namespace string) (*unstructured.Unstructured, error) {
+					return nil, errors.New("connection refused")
+				},
+			},
+			wantSuccess: false,
+			checkOutputs: func(t *testing.T, result *sdk.OperationResult, ext *Extension) {
+				t.Helper()
+				ext.mu.Lock()
+				defer ext.mu.Unlock()
+				if len(ext.generatedNamespaces) != 0 {
+					t.Errorf("expected no tracked namespaces on error, got %d", len(ext.generatedNamespaces))
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ext := &Extension{
+				Extension: sdk.NewExtension(sdk.ExtensionInfo{Name: "test"}),
+				client:    tt.client,
+			}
+
+			req := &sdk.OperationRequest{Args: tt.args}
+			result, err := ext.handleCreateNamespace(context.Background(), req)
+
+			if err != nil {
+				t.Fatalf("handleCreateNamespace() returned error: %v", err)
+			}
+			if result.Success != tt.wantSuccess {
+				t.Errorf("handleCreateNamespace() success = %v, want %v (error: %s)", result.Success, tt.wantSuccess, result.Error)
+			}
+			if tt.checkOutputs != nil {
+				tt.checkOutputs(t, result, ext)
+			}
+		})
+	}
+}
+
+func TestHandleDeleteGeneratedNamespaces(t *testing.T) {
+	tests := []struct {
+		name        string
+		tracked     []string
+		client      *mockClient
+		wantSuccess bool
+		checkTracked func(t *testing.T, ext *Extension)
+	}{
+		{
+			name:        "no tracked namespaces",
+			tracked:     nil,
+			client:      &mockClient{},
+			wantSuccess: true,
+		},
+		{
+			name:    "successful deletion of two namespaces",
+			tracked: []string{"vm-test-abc123", "vm-test-def456"},
+			client: &mockClient{
+				deleteFn: func(ctx context.Context, gvr schema.GroupVersionResource, name, namespace string, opts metav1.DeleteOptions) error {
+					return nil
+				},
+			},
+			wantSuccess: true,
+			checkTracked: func(t *testing.T, ext *Extension) {
+				t.Helper()
+				ext.mu.Lock()
+				defer ext.mu.Unlock()
+				if len(ext.generatedNamespaces) != 0 {
+					t.Errorf("expected tracking cleared, got %d namespaces", len(ext.generatedNamespaces))
+				}
+			},
+		},
+		{
+			name:    "not-found error silently ignored",
+			tracked: []string{"vm-test-gone"},
+			client: &mockClient{
+				deleteFn: func(ctx context.Context, gvr schema.GroupVersionResource, name, namespace string, opts metav1.DeleteOptions) error {
+					return apierrors.NewNotFound(schema.GroupResource{Resource: "namespaces"}, name)
+				},
+			},
+			wantSuccess: true,
+		},
+		{
+			name:    "non-not-found error causes failure",
+			tracked: []string{"vm-test-err"},
+			client: &mockClient{
+				deleteFn: func(ctx context.Context, gvr schema.GroupVersionResource, name, namespace string, opts metav1.DeleteOptions) error {
+					return errors.New("permission denied")
+				},
+			},
+			wantSuccess: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ext := &Extension{
+				Extension:           sdk.NewExtension(sdk.ExtensionInfo{Name: "test"}),
+				client:              tt.client,
+				generatedNamespaces: tt.tracked,
+			}
+
+			req := &sdk.OperationRequest{Args: map[string]any{}}
+			result, err := ext.handleDeleteGeneratedNamespaces(context.Background(), req)
+
+			if err != nil {
+				t.Fatalf("handleDeleteGeneratedNamespaces() returned error: %v", err)
+			}
+			if result.Success != tt.wantSuccess {
+				t.Errorf("handleDeleteGeneratedNamespaces() success = %v, want %v (error: %s)", result.Success, tt.wantSuccess, result.Error)
+			}
+			if tt.checkTracked != nil {
+				tt.checkTracked(t, ext)
+			}
+		})
+	}
+}
+
+func TestGenerateID(t *testing.T) {
+	id, err := generateID(8)
+	if err != nil {
+		t.Fatalf("generateID() error: %v", err)
+	}
+	if len(id) != 8 {
+		t.Errorf("expected 8-char id, got %q (len=%d)", id, len(id))
+	}
+	for _, c := range id {
+		if !strings.ContainsRune(alphanumeric, c) {
+			t.Errorf("id contains invalid character %q", string(c))
+		}
+	}
+
+	// Verify uniqueness (two calls should produce different results)
+	id2, err := generateID(8)
+	if err != nil {
+		t.Fatalf("generateID() error: %v", err)
+	}
+	if id == id2 {
+		t.Errorf("expected unique ids, got %q twice", id)
+	}
+}